1. Field
An embodiment of the present invention relates to a pixel and an organic light emitting display device using the same, and more particularly, to an organic light emitting display device using a pixel that has an improved response time.
2. Description of the Related Art
Currently, all sorts of flat panel display devices are being developed, of which flat panel display devices have a lighter weight and a smaller volume as compared to a cathode ray tube.
Especially, an organic light emitting display device among the flat panel display devices is receiving much attention as the next generation display device because the organic light emitting display device has excellent luminance and color purity when displaying an image. The is because the organic light emitting display device uses an organic light emitting diode which is a self-emitting device.
The above-mentioned organic light emitting display device may be divided into a passive matrix organic light emitting display device (PMOLED) and an active matrix organic light emitting display device (AMOLED) according to a way for driving an organic light emitting diode.
The active matrix organic light emitting display device among these includes a plurality of pixels arranged at the intersection between scanning lines and data lines. In addition, each pixel includes the organic light emitting diode and a pixel circuit for driving the organic light emitting diode. The pixel circuit is typically composed of a switching transistor, a driving transistor, and a storage capacitor.
The active matrix organic light emitting display device may be useful in a portable display device, and the like, because of its low electric power consumption.
However, for the active matrix organic light emitting display device, it is possible that the response time is decreased due to a hysteresis of the driving transistor. In other words, when pixels display a white after displaying a black over many frames, it is possible that the response time is decreased. This is because of a continuous off-voltage supplied to the driving transistor during the period for displaying a black, a transistor curve is shifted, and then a target luminance value is not expressed sufficiently at the initial period for displaying a white.